Whenever we copy steps from 1 test case to another, these particular steps having Send Keys operation like enter or arrow down do not work unless they are selected again on double clicking which is very time consuming. It negates the whole idea of copying the entire test case when anyway you have work again on already completed steps.
I’m assuming you’re copying in Manual view?
Did you try copying the code from the Script view and pasting it that way?
I can assure you, I copy stuff around all day and what you’re seeing has never happened to me.